The present invention relates to a multi-leg stand, and more particularly to a tripod having a locking element that can be vertically moved to equally angularly space three legs of the tripod to stably support a vertical main tube or to fold the three legs to one side of the main tube for easily storage of the tripod. The locking element also enables the legs in the spaced position to stand stably without the risk of unexpected folding thereof.
A tripod is frequently used to support a camera in taking a photo, particularly in professional photography, or to support a lighting fixture on a stage. FIGS. 1A to 1D shows the structure of a currently available tripod. As shown, the tripod includes a hollow connecting bar 91, into which a vertical tube (not shown) is inserted to support a lighting fixture or other photographic apparatus on a top thereof; a turning bolt 92 horizontally screwed into the connecting bar 91 for conveniently fixing or loosening the vertical tube to or from the connecting bar 91; and four turning elements 81, 82, 83, and 84 sequentially connected to a lower end of the connecting bar 91 from top to bottom.
As can be more clearly seen from FIGS. 1C and 1D, the second, the third, and the fourth turning element 82, 83, and 84 respectively have a leg 93 sideward extended from a wall thereof. All the legs 93 have a downward bent distal end. Please refer to FIG. 1D. The first turning element 81 is fixed to the lower end of the connecting bar 91 and has a V-shaped notch 81a provided at a lower edge thereof for engaging with a reverse V-shaped projection 82a provided on an upper edge of the second turning element 82 to restrain the second turning element 82 from turning relative to the first turning element 81. The second turning element 82 is provided at a lower edge with two notches 82b and 82c for selectively engaging with a projection 83a provided on an upper edge of the third turning element 83. Similarly, the third turning element 83 is provided at a lower edge with a projection 83b for selectively engaging with one of two notches 84a, 84b provided on an upper edge of the fourth turning element 84.
The conventional tripod shown in FIGS. 1A to 1D also includes an upper central tube 98, a lower central tube 99, and a bottom cap 96 sealing a lower end of the lower central tube 99. The four turning elements 81 to 84 are actually sequentially mounted around the upper and the lower central tube 98, 99. A bolt 95 is disposed in the central tubes 98, 99 to downward extend a lower end through the bottom cap 96 to engage with a nut 97. A spring 94 is put around the bolt 95 at a section thereof located in the lower central tube 99. When the spring 94 is elastically extended, the third and the fourth turning element 83, 84 are allowed to disengage from each other to turn about the lower central tube 99. At this point, an operator may select to engage the projection 83b with one of the two notches 84a and 84b for the legs 93 to space from one another for use, as shown in FIG. 1A, or to locate at the same side for storage, as shown in FIG. 1B.
In the above-described conventional tripod, it is the spring 94 that controls the locating of the turning elements 83, 84 and the legs 93. With this structure, the legs 93 of the tripod tend to move and cause dangers when they are unexpectedly impacted or collided. When the tripod with the legs in the spaced position is tilted over due to any external force, the photographic apparatus or lighting fixture supported on the tripod would become damaged, and workers nearby the tripod might be injured.
Another problem with the above-described conventional tripod is the third and the fourth turning element 83, 84 may be freely turned leftward or rightward. A negligent operator might have to take more time to set the turning elements 83, 84 and the legs 93 to their correct positions.
Moreover, due to a pull force of the spring 94, the operator must apply a consideraby large force to disengage the projection 83b from the notch 84a or 84b in order to turn the turning elements 83, 84. Under this condition, the turning of the turning elements must be completed with two hands and is therefore inconvenient to the operator.
It is therefore a primary object of the present invention to provide a multi-leg stand having legs that could be conveniently angularly spaced or folded by an operator with only one hand.
Another object of the present invention is to provide a multi-leg stand having legs that are not subject to the risk of unexpected folding even if they are impacted by a strong external force.
To achieve the above and other objects, the multi-leg stand of the present invention mainly includes a vertical main tube and a tripod structure connected to a lower end of the main tube. The tripod structure includes an inner tube around which a locking element and three unions are sequentially mounted from top to bottom. Three legs are separately connected at inner ends to the three unions. When the locking element engages with the first union at a first locking position, the three legs are folded to locate at the same side of the main tube, and when the locking element engages with the first union at a second locking position, the three legs are equally angularly spaced and radially extended. And, when the locking element is in a releasing position on the inner tube, the three unions may be freely turned in one direction with only one hand to quickly and accurately move into the folded or the spaced position.
Since the locking element must be manually pushed upward to enable turning of the unions, the unions are always firmly held to the locked position after the legs are moved to their spaced position without the risk of being unexpectedly folded.